[PATCH] kmod-native: Add back-up implementation of be32toh().

[Randy MacLeod <Randy.MacLeod@windriver.com>]

Older hosts may not have the be32toh function defined. Check for this and
fall back to checking the endianness and calling bswap_32 directly if needed.
This works on both old and new hosts.

Signed-off-by: Randy MacLeod <Randy.MacLeod@windriver.com>
---
 configure.ac                |  1 +
 libkmod/libkmod-signature.c | 14 +++++++++++++-
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index 40e54cf..de2ee49 100644
--- a/configure.ac
+++ b/configure.ac
@@ -45,6 +45,7 @@ PKG_PROG_PKG_CONFIG
 AC_CHECK_FUNCS_ONCE(__xstat)
 AC_CHECK_FUNCS_ONCE([__secure_getenv secure_getenv])
 AC_CHECK_FUNCS_ONCE([finit_module])
+AC_CHECK_FUNCS_ONCE([be32toh])
 
 # dietlibc doesn't have st.st_mtim struct member
 AC_CHECK_MEMBERS([struct stat.st_mtim], [], [], [#include <sys/stat.h>])
diff --git a/libkmod/libkmod-signature.c b/libkmod/libkmod-signature.c
index 6237ab7..791d092 100644
--- a/libkmod/libkmod-signature.c
+++ b/libkmod/libkmod-signature.c
@@ -18,7 +18,7 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
-#include <endian.h>
+#include <byteswap.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
@@ -26,6 +26,18 @@
 
 #include "libkmod-internal.h"
 
+/* be32toh is usually a macro definend in <endian.h>, but it might be
+ * a function in some system so check both, and if neither is defined
+ * then define be32toh (for RHEL 5).
+ */
+#if !defined(HAVE_BE32TOH) && !defined(be32toh)
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+#define be32toh(x) __bswap_32 (x)
+#else
+#define be32toh(x) (x)
+#endif
+#endif
+
 /* These types and tables were copied from the 3.7 kernel sources.
  * As this is just description of the signature format, it should not be
  * considered derived work (so libkmod can use the LGPL license).
-- 
1.8.2.1